A grid substation is where transmission voltages come to be stepped up/stepped down in three phase transformers. Electrical substations are mandatory for all the processes of the power grid. Electrical equipment represents essential scope of devices used to generate electrical power from the substations. Such equipment is installed in the substations for communication, relaying or for supervisory control. It protects the power system component against abnormal conditions such as faults. Substations also allow engineers to diagnose problems with the system and perform diagnostics on the system itself (and the substation equipment).
Recommended tests:
- Capacitance and dissipation factor (C-tan δ)
- Turns ratio
- Winding resistance (only on current transformers)
- Excitation Current (only on current transformers)
- Knee of point (only on current transformers)
- Polarity check
- Insulation resistance
- Burden
- BDV Test
Recommended tests:
- Contact resistance
- Opening and Closing Time
- Insulation resistance
Recommended tests:
- Contact resistance
Recommended tests:
- Capacitance and dissipation factor (C-tan δ)
- Winding resistance
- Winding inductance
- Insulation resistance
Recommended activities:
- Depth discharge
- Measurement of the voltage during discharge cells
- Measurement of the electrolyte density of the cells (only on acid stationary batteries)
Recommended tests:
- Measurement of the capacitance of the batteries
- Insulation resistance
Recommended tests:
- Very Low Frequency (VLF) Testing
- Insulation resistance
- Locating a defect
Primary and secondary testing of the protection relays
- Protection relays testing with primary injection single phase up to 800A
- Three phase systems up to 35A
Recommended tests:
- Measurement of discharge current
- Insulation resistance
Thermal imaging can locate the hot spots of the weak contacts, asymmetrical load in the electrical equipment installed in the power facilities and sub-stations
Recommended tests:
- Earth resistance
- Specific earth resistance (soil resistivity)
- Step and contact voltage
- Continuity of the grounding system
- Prevectron lightning protection
Recommended tests:
- Prospective Short Circuit Current (Z line)
- Prospective Earth Fault Current (Z loop)
- Insulation Resistance
- Phase sequence check
- Continuity of grounding
